Betaseron

Drug overview for BETASERON (interferon beta-1b):

Generic name: INTERFERON BETA-1B (IN-ter-FEER-on BAY-ta-wun-bee)
Drug class: Multiple Sclerosis Agents, General
Therapeutic class: Multiple Sclerosis Agents

Interferon beta, a biosynthetic (recombinant DNA origin) form of endogenous human interferon beta, has immunomodulatory and disease-modifying activity in multiple sclerosis (MS). Interferon beta is available as interferon beta-1a and interferon beta-1b.

No enhanced Uses information available for this drug.

DRUG IMAGES

BETASERON 0.3 MG KIT

The following indications for BETASERON (interferon beta-1b) have been approved by the FDA:

Indications:
Relapsing form of multiple sclerosis
Secondary progressive multiple sclerosis

Professional Synonyms:
Multiple sclerosis, relapsing form

Dosing information for BETASERON
DRUG LABEL	DOSING TYPE	DOSING INSTRUCTIONS
BETASERON 0.3 MG VIAL	Maintenance	Adults inject 1 milliliter (0.25 mg) by subcutaneous route every other day
BETASERON 0.3 MG KIT	Maintenance	Adults inject 1 milliliter (0.25 mg) by subcutaneous route every other day

The following drug interaction information is available for BETASERON (interferon beta-1b):

Contraindicated
Severe
Moderate

There are 4 contraindications. These drug combinations generally should not be dispensed or administered to the same patient. A manufacturer label warning that indicates the contraindication warrants inclusion of a drug combination in this category, regardless of clinical evidence or lack of clinical evidence to support the contraindication.

Drug Interaction	Drug Names
Efalizumab; Natalizumab/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient. MECHANISM OF ACTION: Natalizumab,(1-3) efalizumab,(4) immunosuppressives, and immunomodulators all suppress the immune system. CLINICAL EFFECTS: Concurrent use of natalizumab(1-3) or efalizumab(4) with immunosuppressives or immunomodulators may result in an increased risk of infections, including progressive multifocal leukoencephalopathy (PML), an opportunistic infection caused by the JC virus (JCV). PREDISPOSING FACTORS: Previous JCV infection, longer duration of natalizumab treatment - especially if greater than 2 years, and prior or concomitant treatment with immunosuppressant medication are all independent risk factors which increase the risk for PML.(1,5) The FDA has estimated PML incidence stratified by risk factors: If anti-JCV antibody positive, no prior immunosuppressant use and natalizumab treatment less than 25 months, incidence <1/1,000. If anti-JCV antibody positive, history of prior immunosuppressant use and natalizumab treatment less than 25 months, incidence 2/1,000 If anti-JCV antibody positive, no prior immunosuppressant use and natalizumab treatment 25-48 months, incidence 4/1,000 If anti-JCV antibody positive, history of prior immunosuppressant use and natalizumab treatment 25-48 months, incidence 11/1,000. PATIENT MANAGEMENT: The US manufacturer of natalizumab states patients with Crohn's disease should not receive concurrent immunosuppressants, with the exception of limited overlap of corticosteroids, due to the increased risk for PML. For new natalizumab patients currently receiving chronic oral corticosteroids for Crohn's Disease, begin corticosteroid taper when therapeutic response to natalizumab has occurred. If corticosteroids cannot be discontinued within six months of starting natalizumab, discontinue natalizumab.(3) The US manufacturer of natalizumab states that natalizumab should not ordinarily be used in multiple sclerosis patients receiving immunosuppressants or immunomodulators due to the increased risk for PML. Immunosuppressives include, but are not limited to azathioprine, cyclophosphamide, cyclosporine, mercaptopurine, methotrexate, mitoxantrone, mycophenolate, and corticosteroids.(3,6) The UK manufacturer of natalizumab states that concurrent use with immunosuppressives or antineoplastic agents is contraindicated.(1) The Canadian manufacturer of natalizumab states that natalizumab should not be used with immunosuppressive or immunomodulatory agents.(2) The US manufacturer of certolizumab states that concurrent therapy with natalizumab is not recommended.(7) DISCUSSION: Progressive multifocal leukoencephalopathy has been reported in patients receiving concurrent natalizumab were recently or concomitantly taking immunomodulators or immunosuppressants.(1-5,8,9) In a retrospective cohort study of multiple sclerosis patients newly initiated on a disease-modifying therapy, use of high-efficacy agents (alemtuzumab, natalizumab, or ocrelizumab) resulted in the same risk of overall infections as moderate-efficacy agents, but there was an elevated risk of serious infections (adjusted hazard ratio [aHR] = 1.24, 95% confidence interval (CI) = 1.06-1.44) and UTIs (aHR = 1.21, 95% CI = 1.14-1.30).(10)	TYRUKO, TYSABRI
Live Vaccines; Live BCG/Selected Immunosuppressive Agents SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient. MECHANISM OF ACTION: A variety of disease modifying agents suppress the immune system. Immunocompromised patients may be at increased risk for uninhibited replication after administration of live, attenuated vaccines or intravesicular BCG. Immune response to vaccines may be decreased during periods of immunocompromise.(1) CLINICAL EFFECTS: The expected serum antibody response may not be obtained and/or the vaccine may result in illness.(1) After instillation of intravesicular BCG, immunosuppression may interfere with local immune response, or increase the severity of mycobacterial infection following inadvertent systemic exposure.(2) PREDISPOSING FACTORS: Immunosuppressive diseases (e.g. hematologic malignancies, HIV disease), treatments (e.g. radiation) and drugs may all increase the magnitude of immunodeficiency. PATIENT MANAGEMENT: The Centers for Disease Control(CDC) Advisory Committee on Immunization Practices (ACIP) states that live-virus and live, attenuated vaccines should not be administered to patients who are immunocompromised. The magnitude of immunocompromise and associated risks should be determined by a physician.(1) For patients scheduled to receive chemotherapy, vaccination should ideally precede the initiation of chemotherapy by 14 days. Patients vaccinated while on immunosuppressive therapy or in the 2 weeks prior to starting therapy should be considered unimmunized and should be revaccinated at least 3 months after discontinuation of therapy.(1) Patients who receive anti-B cell therapies should not receive live vaccines for at least 6 months after such therapies due to a prolonged duration of immunosuppression. An exception is the Zoster vaccine, which can be given at least 1 month after receipt of anti-B cell therapies.(1) The US manufacturer of abatacept states live vaccines should not be given during or for up to 3 months after discontinuation of abatacept.(2) The US manufacturer of live BCG for intravesicular treatment of bladder cancer states use is contraindicated in immunosuppressed patients.(3) The US manufacturer of daclizumab states live vaccines are not recommended during and for up to 4 months after discontinuation of treatment.(4) The US manufacturer of guselkumab states that live vaccines should be avoided during treatment with guselkumab.(5) The US manufacturer of inebilizumab-cdon states that live vaccines are not recommended during treatment and after discontinuation until B-cell repletion. Administer all live vaccinations at least 4 weeks prior to initiation of inebilizumab-cdon.(6) The US manufacturer of ocrelizumab states that live vaccines are not recommended during treatment and until B-cell repletion occurs after discontinuation of therapy. Administer all live vaccines at least 4 weeks prior to initiation of ocrelizumab.(7) The US manufacturer of ozanimod states that live vaccines should be avoided during and for up to 3 months after discontinuation of ozanimod.(8) The US manufacturer of siponimod states that live vaccines are not recommended during treatment and for up to 4 weeks after discontinuation of treatment.(9) The US manufacturer of ustekinumab states BCG vaccines should not be given in the year prior to, during, or the year after ustekinumab therapy.(10) The US manufacturer of satralizumab-mwge states that live vaccines are not recommended during treatment and should be administered at least four weeks prior to initiation of satralizumab-mwge.(11) The US manufacturer of ublituximab-xiiy states that live vaccines are not recommended during treatment and until B-cell recovery. Live vaccines should be administered at least 4 weeks prior to initiation of ublituximab-xiiy.(12) The US manufacturer of etrasimod states that live vaccines should be avoided during and for 5 weeks after treatment. Live vaccines should be administered at least 4 weeks prior to initiation of etrasimod.(13) The US manufacturer of emapalumab-lzsg states that live vaccines should not be administered to patients receiving emapalumab-lzsg and for at least 4 weeks after the last dose of emapalumab-lzsg. The safety of immunization with live vaccines during or following emapalumab-lzsg therapy has not been studied.(14) DISCUSSION: Killed or inactivated vaccines do not pose a danger to immunocompromised patients.(1) Patients with a history of leukemia who are in remission and have not received chemotherapy for at least 3 months are not considered to be immunocompromised.(1)	ACAM2000 (NATIONAL STOCKPILE), ADENOVIRUS TYPE 4, ADENOVIRUS TYPE 4 AND TYPE 7, ADENOVIRUS TYPE 7, BCG (TICE STRAIN), BCG VACCINE (TICE STRAIN), DENGVAXIA, ERVEBO (NATIONAL STOCKPILE), FLUMIST 2025-2026, FLUMIST HOME 2025-2026, M-M-R II VACCINE, PRIORIX, PROQUAD, ROTARIX, ROTATEQ, STAMARIL, VARIVAX VACCINE, VAXCHORA ACTIVE COMPONENT, VAXCHORA VACCINE, VIVOTIF, YF-VAX
Talimogene laherparepvec/Selected Immunosuppressants SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient. MECHANISM OF ACTION: Talimogene laherparepvec is a live, attenuated herpes simplex virus.(1) CLINICAL EFFECTS: Concurrent use of talimogene laherparepvec in patients receiving immunosuppressive therapy may cause a life-threatening disseminated herpetic infection.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Talimogene laherparepvec is contraindicated in immunosuppressed patients.(1) The magnitude of immunocompromise and associated risks due to immunosuppressant drugs should be determined by a physician. DISCUSSION: Concurrent use of talimogene laherparepvec in patients receiving immunosuppressive therapy may cause a life-threatening disseminated herpetic infection.(1)	IMLYGIC
Nadofaragene Firadenovec/Selected Immunosuppressants SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient. MECHANISM OF ACTION: Nadofaragene firadenovec may contain low levels of replication-competent adenovirus.(1) CLINICAL EFFECTS: Concurrent use of nadofaragene firadenovec in patients receiving immunosuppressive therapy may cause disseminated adenovirus infection.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Individuals who are immunosuppressed or immune-deficient should not receive nadofaragene firadenovec.(1) DISCUSSION: Nadofaragene firadenovec is a non-replicating adenoviral vector-based gene therapy but may contain low levels of replication-competent adenovirus. Immunocompromised persons, including those receiving immunosuppressant therapy, may be at risk for disseminated adenovirus infection.(1)	ADSTILADRIN

There are 20 severe interactions. These drug interactions can produce serious consequences in most patients. Actions required for severe interactions include, but are not limited to, discontinuing one or both agents, adjusting dosage, altering administration scheduling, and providing additional patient monitoring. Review the full interaction monograph for more information.

Drug Interaction	Drug Names
Hydroxyurea/Interferon SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: The exact mechanism is unknown. CLINICAL EFFECTS: Concurrent or recent use of interferon may increase the risk of cutaneous vascular toxicities, including vasculitic ulcerations and gangrene.(1,2) PREDISPOSING FACTORS: The interaction has been noted in patients treated with hydroxyurea for myeloproliferative disorders.(1,2) PATIENT MANAGEMENT: Monitor patients receiving concurrent therapy and patients receiving hydroxyurea alone who have recently received interferon closely for cutaneous vasculitic ulcerations. Discontinue hydroxyurea in patients who develop cutaneous vasculitic ulcerations.(1,2) DISCUSSION: Cutaneous vasculitic toxicities, including vasculitic ulcerations and gangrene, have occurred in patients with myeloproliferative disorders during therapy with hydroxyurea. These vasculitic toxicities were reported most often in patients with a history of, or currently receiving, interferon therapy.(1,2)	DROXIA, HYDREA, HYDROXYUREA, SIKLOS, XROMI
Deferiprone/Selected Myelosuppressive Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of deferiprone with other drugs known to be associated with neutropenia or agranulocytosis may increase the frequency or risk for severe toxicity.(1) CLINICAL EFFECTS: Concurrent use of deferiprone and myelosuppressive agents may result in severe neutropenia or agranulocytosis, which may be fatal. PREDISPOSING FACTORS: Agranulocytosis may be less common in patients receiving deferiprone for thalassemia, and more common in patients treated for other systemic iron overload conditions (e.g. myelodysplastic syndromes, sickle cell disease).(2,3) Inadequate monitoring appears to increase the risk for severe outcomes. Manufacturer post market surveillance found that in all fatal cases of agranulocytosis reported between 1999 and 2005, data on weekly white blood count (WBC) monitoring was missing. In three fatal cases, deferiprone was continued for two to seven days after the detection of neutropenia or agranulocytosis.(2) PATIENT MANAGEMENT: If possible, discontinue one of the drugs associated with risk for neutropenia or agranulocytosis. If alternative therapy is not available, documentation and adherence to the deferiprone monitoring protocol is essential. Baseline absolute neutrophil count (ANC) must be at least 1,500/uL prior to starting deferiprone. Monitor ANC weekly during therapy. If infection develops, interrupt deferiprone therapy and monitor ANC more frequently. If ANC is less than 1,500/uL but greater than 500/uL, discontinue deferiprone and any other drugs possibly associated with neutropenia. Initiate ANC and platelet counts daily until recovery (i.e. ANC at least 1,500/uL). If ANC is less than 500/uL, discontinue deferiprone, evaluate patient and hospitalize if appropriate. Do not resume deferiprone unless potential benefits outweigh potential risks.(1) DISCUSSION: Drugs linked to this monograph have an FDA Boxed Warning for risk of neutropenia, agranulocytosis, or pancytopenia, or have > 5% risk for neutropenia and/or warnings describing risk for myelosuppression in manufacturer prescribing information.(1-25) In pooled clinical studies submitted to the FDA, 6.1% of deferiprone patients met criteria for neutropenia and 1.7% of patients developed agranulocytosis.(1) The time to onset of agranulocytosis was highly variable with a range of 65 days to 9.2 years (median, 161 days).(3)	DEFERIPRONE, DEFERIPRONE (3 TIMES A DAY), FERRIPROX, FERRIPROX (2 TIMES A DAY), FERRIPROX (3 TIMES A DAY)
Tofacitinib/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of tofacitinib and azathioprine, other biologic disease-modifying antirheumatic drugs (DMARDs), or potent immunosuppressants may result in additive or synergistic effects on the immune system.(1) CLINICAL EFFECTS: Concurrent use of tofacitinib and azathioprine, other biologic DMARDs, or potent immunosuppressants use may increase the risk of serious infections.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Tofacitinib should not be used concurrently with azathioprine, other biologic DMARDs, or cyclosporine.(1) Patient should be monitored for decreases in lymphocytes and neutrophils. Therapy should be adjusted based on the indication. - For all indications: If absolute neutrophil count (ANC) or lymphocyte count is less than 500 cells/mm3, discontinue tofacitinib. - For rheumatoid arthritis or psoriatic arthritis and absolute neutrophil count (ANC) 500 to 1000 cells/mm3: interrupt dosing. When ANC is greater than 1000 cells/mm3, resume Xeljanz 5 mg twice daily or Xeljanz XR 11 mg once daily. - For ulcerative colitis and ANC 500 to 1000 cells/mm3: -If taking Xeljanz 10 mg twice daily, decrease to 5 mg twice daily. When ANC is greater than 1000 cells/mm3, increase to 10 mg twice daily based on clinical response. -If taking Xeljanz 5 mg twice daily, interrupt dosing. When ANC is greater than 1000 cells/mm3, resume 5 mg twice daily. -If taking Xeljanz XR 22 mg once daily, decrease to 11 mg once daily. When ANC is greater than 1000 cells/mm3, increase to 22 mg once daily based on clinical response. -If taking Xeljanz XR 11 mg once daily, interrupt dosing. When ANC is greater than 1000 cells/mm3, resume 11 mg once daily. - For polyarticular course juvenile idiopathic arthritis (pcJIA) and ANC 500 to 1000 cells/mm3: interrupt dosing until ANC is greater than 1000 cells/mm3.(1) DISCUSSION: Concurrent use of tofacitinib and azathioprine, other biologic DMARDs, or potent immunosuppressants may increase the risk of infection.(1)	TOFACITINIB CITRATE, XELJANZ, XELJANZ XR
Clozapine/Selected Myelosuppressive Agents SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Clozapine and other myelosuppressive agents may be associated with neutropenia or agranulocytosis.(2) CLINICAL EFFECTS: Moderate neutropenia, even if due to combination therapy, may require abrupt discontinuation of clozapine resulting in decompensation of the patient's psychiatric disorder (e.g. schizophrenia). The disease treated by the myelosuppressive agent may be compromised if myelosuppression requires dose reduction, delay, or discontinuation of the myelosuppressive agent. Undetected severe neutropenia or agranulocytosis may be fatal. PREDISPOSING FACTORS: Low white blood counts prior to initiation of the myelosuppressive agent may increase risk for clinically significant neutropenia. PATIENT MANAGEMENT: If a patient stabilized on clozapine therapy requires treatment with a myelosuppressive agent, the clozapine prescriber should consult with prescriber of the myelosuppressive agent (e.g. oncologist) to discuss treatment and monitoring options.(2) More frequent ANC monitoring or treatment alternatives secondary to neutropenic episodes may need to be considered. Clozapine is only available through a restricted distribution system which requires documentation of the absolute neutrophil count (ANC) prior to dispensing.(1-2) For most clozapine patients, clozapine treatment must be interrupted for a suspected clozapine-induced ANC < 1000 cells/microliter. For patients with benign ethnic neutropenia (BEN), treatment must be interrupted for suspected clozapine-induced neutropenia < 500 cells/microliter.(2) DISCUSSION: Clozapine is only available through a restricted distribution system which requires documentation of the ANC prior to dispensing.(1) Agents linked to this interaction generally have > 5% risk for neutropenia and/or warnings describing risk for myelosuppression in manufacturer prescribing information.(3-26)	CLOZAPINE, CLOZAPINE ODT, CLOZARIL, VERSACLOZ
Selected Multiple Sclerosis Agents/Immunosuppressants; Immunomodulators SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Ocrelizumab or ofatumumab in combination with immunosuppressives and immune-modulators all suppress the immune system.(1,2) CLINICAL EFFECTS: Concurrent use of ocrelizumab or ofatumumab with immunosuppressive or immune-modulating agents may result in an increased risk of serious infections, such as disseminated herpetic infection or progressive multifocal leukoencephalopathy (PML), an opportunistic infection caused by the JC virus (JCV).(1,2) PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications. PATIENT MANAGEMENT: The ocrelizumab US prescribing information states: - Ocrelizumab and other immune-modulating or immunosuppressive therapies, (including immunosuppressant doses of corticosteroids) are expected to increase the risk of immunosuppression, and the risk of additive immune system effects must be considered if these therapies are coadministered with ocrelizumab. When switching from drugs with prolonged immune effects, such as daclizumab, fingolimod, natalizumab, teriflunomide, or mitoxantrone, the duration and mode of action of these drugs must be considered to avoid unintended additive immunosuppressive effects when initiating ocrelizumab.(1) The ofatumumab US prescribing information states: - Ofatumumab and other immunosuppressive therapies (including systemic corticosteroids) may have the potential for increased immunosuppressive effects and increase the risk of infection. When switching between therapies, the duration and mechanism of action of each therapy should be considered due to the potential for additive immunosuppressive effects. Ofatumumab for MS therapy has not been studied in combination with other MS agents that suppress the immune system.(2) DISCUSSION: Fatal disseminated herpes zoster and herpes simplex infections and cases of progressive multifocal leukoencephalopathy (PML) have been reported in patients who previously received immunomodulators or immunosuppressants.(1,2) In a retrospective cohort study of multiple sclerosis patients newly initiated on a disease-modifying therapy, use of high-efficacy agents (alemtuzumab, natalizumab, or ocrelizumab) resulted in the same risk of overall infections as moderate-efficacy agents, but there was an elevated risk of serious infections (adjusted hazard ratio [aHR] = 1.24, 95% confidence interval (CI) = 1.06-1.44) and UTIs (aHR = 1.21, 95% CI = 1.14-1.30).(3)	KESIMPTA PEN, OCREVUS, OCREVUS ZUNOVO
Upadacitinib/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Upadacitinib, immunosuppressives, and immunomodulators all suppress the immune system. CLINICAL EFFECTS: Concurrent use of upadacitinib with immunosuppressives or immunomodulators may result in an increased risk of serious infections. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: The US manufacturer of upadacitinib states that concurrent use of upadacitinib with immunosuppressives or immunomodulators is not recommended. DISCUSSION: Serious infections have been reported in patients receiving upadacitinib. Reported infections included pneumonia, cellulitis, tuberculosis, multidermatomal herpes zoster, oral/esophageal candidiasis, cryptococcosis. Reports of viral reactivation, including herpes virus reactivation and hepatitis B reactivation, were reported in clinical studies with upadacitinib.(1)	RINVOQ, RINVOQ LQ
Inebilizumab/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Inebilizumab, immunosuppressives, and immunomodulators all suppress the immune system.(1) CLINICAL EFFECTS: Concurrent use of inebilizumab with immunosuppressive or immunomodulating agents may result in myelosuppression including neutropenia resulting in an increased risk for serious infections.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: The US manufacturer of inebilizumab states that the concurrent use of inebilizumab with immunosuppressive agents, including systemic corticosteroids, may increase the risk of infection. If concurrent therapy is warranted, consider the risk of additive immune suppression and monitor based on prescribing information for both agents.(1) DISCUSSION: Inebilizumab has not been studied in combination with other immunosuppressants. If concurrent therapy is warranted, consider the potential for increased immunosuppressive risks from both agents. The most common infections reported by inebilizumab treated patients in the randomized and open-label clinical trial periods included urinary tract infections (20%), nasopharyngitis (13%), upper respiratory tract infections (8%), and influenza (7%). Although there been no cases of Hepatitis B virus reactivation or progressive multifocal leukoencephalopathy reported in patients taking inebilizumab, these infections have been observed in patients taking other B-cell-depleting antibodies.(1)	UPLIZNA
Baricitinib/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of baricitinib with other biologic disease-modifying antirheumatic drugs (DMARDs) or potent immunosuppressants such as azathioprine or cyclosporine may result in additive or synergistic effects on the immune system. CLINICAL EFFECTS: Concurrent use of baricitinib with other biologic DMARDs or potent immunosuppressants such as azathioprine or cyclosporine may increase the risk of serious infections.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: The US manufacturer of baricitinib states that concurrent use of baricitinib with biologic DMARDs or potent immunosuppressants is not recommended.(1) DISCUSSION: Most patients who developed serious infections while being treated with baricitinib were on concomitant immunosuppressants like methotrexate and corticosteroids. The combination of baricitinib with other biologic DMARDs has not been studied.(1)	OLUMIANT
Leflunomide; Teriflunomide/Selected Immunosuppressants SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of leflunomide or teriflunomide and potent immunosuppressants may result in additive or synergistic effects on the immune system.(1,2) Leflunomide is a prodrug and is converted to its active metabolite teriflunomide.(1) CLINICAL EFFECTS: Concurrent use of leflunomide or teriflunomide with immunosuppressants may result in an increased risk of serious infections, including opportunistic infections, especially Pneumocystis jiroveci pneumonia, tuberculosis (including extra-pulmonary tuberculosis), and aspergillosis. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: If leflunomide or teriflunomide is used concurrently with immunosuppressive agents, chronic CBC monitoring should be performed more frequently, every month instead of every 6 to 8 weeks. If bone marrow suppression or a serious infection occurs, leflunomide or teriflunomide should be stopped and rapid drug elimination procedure should be performed.(1,2) DISCUSSION: Pancytopenia, agranulocytosis and thrombocytopenia have been reported in patients receiving leflunomide or teriflunomide alone, but most frequently in patients taking concurrent immunosuppressants.(1,2) Severe and potentially fatal infections, including sepsis, have been reported in patients receiving leflunomide or teriflunomide, especially Pneumocystis jiroveci pneumonia and aspergillosis. Tuberculosis has also been reported.(1,2)	ARAVA, AUBAGIO, LEFLUNICLO, LEFLUNOMIDE, TERIFLUNOMIDE
Ponesimod/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Ponesimod in combination with immunosuppressives and immune-modulators all suppress the immune system.(1) CLINICAL EFFECTS: Concurrent use of ponesimod with immunosuppressive or immune-modulating agents may result in an increased risk of serious infections, such as disseminated herpetic infection, cryptococcal infection, or progressive multifocal leukoencephalopathy (PML), an opportunistic infection caused by the JC virus (JCV).(1) PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications. PATIENT MANAGEMENT: The ponesimod US prescribing information states ponesimod has not been studied in combination with anti-neoplastic, immune-modulating, or immunosuppressive therapies. Caution should be used during concomitant administration because of the risk of additive immune effects during therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, the half-life and mode of action of these drugs must be considered in order to avoid unintended additive immunosuppressive effects. Initiating treatment with ponesimod after alemtuzumab is not recommended. However, ponesimod can generally be started immediately after discontinuation of beta interferon or glatiramer acetate.(1) DISCUSSION: Fatal disseminated herpes zoster and herpes simplex infections, cryptococcal meningitis, disseminated cryptococcal infections, and cases of progressive multifocal leukoencephalopathy (PML) have been reported in patients who previously received immunomodulators or immunosuppressants.(1)	PONVORY
Sodium Iodide I 131/Myelosuppressives; Immunomodulators SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Sodium iodide I 131 can cause depression of the hematopoetic system. Myelosuppressives and immunomodulators also suppress the immune system.(1) CLINICAL EFFECTS: Concurrent use of sodium iodide I 131 with agents that cause bone marrow depression, including myelosuppressives or immunomodulators, may result in an enhanced risk of hematologic disorders, including anemia, blood dyscrasias, bone marrow depression, leukopenia, and thrombocytopenia. Bone marrow depression may increase the risk of serious infections and bleeding.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: The US manufacturer of sodium iodide I 131 states that concurrent use with bone marrow depressants may enhance the depression of the hematopoetic system caused by large doses of sodium iodide I 131.(1) Sodium iodide I 131 causes a dose-dependent bone marrow suppression, including neutropenia or thrombocytopenia, in the 3 to 5 weeks following administration. Patients may be at increased risk of infections or bleeding during this time. Monitor complete blood counts within one month of therapy. If results indicate leukopenia or thrombocytopenia, dosimetry should be used to determine a safe sodium iodide I 131 activity.(1) DISCUSSION: Hematologic disorders including death have been reported with sodium iodide I 131. The most common hematologic disorders reported include anemia, blood dyscrasias, bone marrow depression, leukopenia, and thrombocytopenia.(1)	HICON, SODIUM IODIDE I-131
Fingolimod/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Fingolimod in combination with immunosuppressives and immune-modulators all suppress the immune system.(1-3) CLINICAL EFFECTS: Concurrent use of fingolimod with immunosuppressive or immune-modulating agents may result in an increased risk of serious infections, such as disseminated herpetic infection or progressive multifocal leukoencephalopathy (PML), an opportunistic infection caused by the JC virus (JCV).(1-3) PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications. PATIENT MANAGEMENT: Recommendations for fingolimod regarding this interaction differ between regulatory approving agencies. The fingolimod US prescribing information states: - Antineoplastic, immune-modulating, or immunosuppressive therapies, (including corticosteroids) are expected to increase the risk of immunosuppression, and the risk of additive immune system effects must be considered if these therapies are coadministered with fingolimod. When switching from drugs with prolonged immune effects, such as natalizumab, teriflunomide or mitoxantrone, the duration and mode of action of these drugs must be considered to avoid unintended additive immunosuppressive effects when initiating fingolimod.(1) The fingolimod Canadian prescribing information states: - Concurrent use with immunosuppressive or immunomodulatory agents is contraindicated due to the risk of additive immune system effects. However, co-administration of a short course of corticosteroids (up to 5 days) did not increase the overall rate of infection in patients participating Phase III clinical trials.(2) The fingolimod UK specific product characteristics states: - Fingolimod is contraindicated in patients currently receiving immunosuppressive therapies or those immunocompromised by prior therapies. When switching patients from another disease modifying therapy to Gilenya, the half-life and mode of action of the other therapy must be considered in order to avoid an additive immune effect whilst at the same time minimizing the risk of disease activation.(3) DISCUSSION: Fatal disseminated herpes zoster and herpes simplex infections and cases of progressive multifocal leukoencephalopathy (PML) have been reported in patients who previously received immunomodulators or immunosuppressants.(1-3)	FINGOLIMOD, GILENYA, TASCENSO ODT
Ozanimod/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Ozanimod in combination with immunosuppressives and immune-modulators all suppress the immune system.(1) CLINICAL EFFECTS: Concurrent use of ozanimod with immunosuppressive or immune-modulating agents may result in an increased risk of serious infections, such as disseminated herpetic infection or progressive multifocal leukoencephalopathy (PML), an opportunistic infection caused by the JC virus (JCV).(1) PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications. PATIENT MANAGEMENT: The ozanimod US prescribing information state this information regarding this interaction: -Ozanimod has not been studied in combination with anti-neoplastic, immune-modulating, or immunosuppressive therapies. Caution should be used during concomitant administration because of the risk of additive immune effects during therapy and in the week following administration. When switching from drugs with prolonged immune effects, the half-life and mode of action of these drugs must be considered in order to avoid unintended additive immunosuppressive effects. Initiating treatment with ozanimod after alemtuzumab is not recommended. However, ozanimod can generally be started immediately after discontinuation of beta interferon or glatiramer acetate.(1) DISCUSSION: Fatal disseminated herpes zoster and herpes simplex infections and cases of progressive multifocal leukoencephalopathy (PML) have been reported in patients who previously received immunomodulators or immunosuppressants.(1)	ZEPOSIA
Siponimod/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Siponimod in combination with immunosuppressives and immune-modulators all suppress the immune system.(1) CLINICAL EFFECTS: Concurrent use of siponimod with immunosuppressive or immune-modulating agents may result in an increased risk of serious infections, such as disseminated herpetic infection or progressive multifocal leukoencephalopathy (PML), an opportunistic infection caused by the JC virus (JCV).(1) PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications. PATIENT MANAGEMENT: The siponimod US prescribing information state this information regarding this interaction: -Siponimod has not been studied in combination with anti-neoplastic, immune-modulating, or immunosuppressive therapies. Caution should be used during concomitant administration because of the risk of additive immune effects during therapy and in the week following administration. When switching from drugs with prolonged immune effects, the half-life and mode of action of these drugs must be considered in order to avoid unintended additive immunosuppressive effects. Initiating treatment with siponimod after alemtuzumab is not recommended. However, siponimod can generally be started immediately after discontinuation of beta interferon or glatiramer acetate.(1) DISCUSSION: Fatal disseminated herpes zoster and herpes simplex infections and cases of progressive multifocal leukoencephalopathy (PML) have been reported in patients who previously received immunomodulators or immunosuppressants.(1)	MAYZENT
Cladribine Oral/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Cladribine in combination with immunosuppressives and immune-modulators all suppress the immune system.(1-2) CLINICAL EFFECTS: Concurrent use of cladribine with immunosuppressive or immune-modulating agents may result in an increased risk of serious infections, such as disseminated herpetic infection or progressive multifocal leukoencephalopathy (PML), an opportunistic infection caused by the JC virus (JCV).(1-2) PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications. PATIENT MANAGEMENT: Recommendations for cladribine regarding this interaction differ between regulatory approving agencies. The cladribine US prescribing information states: -Concomitant use with myelosuppressive or other immunosuppressive drugs is not recommended. Acute short-term therapy with corticosteroids can be administered. In patients who have previously been treated with immunomodulatory or immunosuppressive drugs, consider potential additive effect, the mode of action, and duration of effect of the other drugs prior to initiation of cladribine.(1) The cladribine Canadian prescribing information states: -Use of cladribine in immunocompromised patients is contraindicated because of a risk of additive effects on the immune system. Acute short-term therapy with corticosteroids can be administered during cladribine treatment.(2) DISCUSSION: Fatal disseminated herpes zoster and herpes simplex infections and cases of progressive multifocal leukoencephalopathy (PML) have been reported in patients who previously received immunomodulators or immunosuppressants.(1-2)	MAVENCLAD
Anifrolumab/Biologic Therapies SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Concurrent use of anifrolumab with other biologic therapies may result in additive or synergistic effects on the immune system.(1) CLINICAL EFFECTS: Concurrent use of anifrolumab with other biologic therapies may increase the risk of serious infections.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: The concurrent use of anifrolumab with other biologic therapies is not recommended.(1) DISCUSSION: The combination of anifrolumab with other biologic therapies has not been studied and is not recommended.(1)	SAPHNELO
Ritlecitinib/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Ritlecitinib, immunosuppressives, and immunomodulators all suppress the immune system. CLINICAL EFFECTS: Concurrent use of ritlecitinib with immunosuppressives or immunomodulators may result in an increased risk of serious infections. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: The US manufacturer of ritlecitinib states that concurrent use of ritlecitinib with other JAK inhibitors, biologic immunomodulators, cyclosporine or other potent immunosuppressants is not recommended.(1) DISCUSSION: Serious infections have been reported in patients receiving ritlecitinib. Reported infections included appendicitis, COVID-19 infection (including pneumonia), and sepsis. Reports of viral reactivation, including herpes virus reactivation was reported in clinical studies with ritlecitinib.(1)	LITFULO
Etrasimod/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Etrasimod causes reversible sequestration of lymphocytes in lymphoid tissues, resulting in a mean 55% decrease in peripheral blood lymphocyte count at 52 weeks.(1) Other immunosuppressives and immune-modulators also suppress the immune system. CLINICAL EFFECTS: Concurrent use of etrasimod with immunosuppressive or immune-modulating agents may result in an increased risk of serious and fatal infections, such as disseminated herpetic infection, cryptococcal infection, or progressive multifocal leukoencephalopathy (PML).(1) PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications increases the risk of adverse effects. PATIENT MANAGEMENT: The etrasimod US prescribing information states etrasimod has not been studied in combination with anti-neoplastic, immune-modulating, or immunosuppressive therapies. Concomitant administration of these therapies with etrasimod should be avoided because of the risk of additive immune effects during therapy and in the weeks following administration. Etrasimod's effect on peripheral lymphocytes may persist for up to 5 weeks after discontinuation.(1) When switching from drugs with prolonged immune effects, the half-life and mode of action of these drugs must be considered in order to avoid unintended additive immunosuppressive effects.(1) DISCUSSION: Fatal disseminated herpes zoster and herpes simplex infections, cryptococcal meningitis, disseminated cryptococcal infections, and cases of progressive multifocal leukoencephalopathy (PML) have been reported in patients treated with other sphingosine-1 phosphate receptor modulators.(1)	VELSIPITY
Ropeginterferon alfa-2b/Slt Immunosuppress; Immunomodulator SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Ropeginterferon alfa-2b and immunosuppressives both suppress the immune system. CLINICAL EFFECTS: Concurrent use of ropeginterferon alfa-2b with immunosuppressives may result in an increased risk of serious infections. PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Avoid concurrent use of myelosuppressive agents.(1-2) If concurrent use cannot be avoided, monitor for effects of excessive immunosuppression. DISCUSSION: In clinical trials, 20% of patients experienced leukopenia. Interferon alfa products may cause fatal or life-threatening infections.(1-2)	BESREMI
Deuruxolitinib/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction. MECHANISM OF ACTION: Deuruxolitinib, immunosuppressives, and immunomodulators all suppress the immune system.(1) CLINICAL EFFECTS: Concurrent use of deuruxolitinib and potent immunosuppressants may increase the risk of serious infections.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: The US manufacturer of deuruxolitinib states that concurrent use of deuruxolitinib with other JAK inhibitors, biologic immunomodulators, cyclosporine or other potent immunosuppressants is not recommended.(1) If concurrent use cannot be avoided, patients should be monitored for signs and symptoms of infection. If a patient develops a serious or opportunistic infection, interrupt deuruxolitinib treatment until the infection is controlled. DISCUSSION: Serious infections have been reported in patients receiving treatment with deuruxolitinib.(1)	LEQSELVI

There are 8 moderate interactions. The clinician should assess the patient’s characteristics and take action as needed. Actions required for moderate interactions include, but are not limited to, discontinuing one or both agents, adjusting dosage, altering administration.

Drug Interaction	Drug Names
Theophylline Derivatives/Selected CYP1A2 Inhibitors SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: CYP1A2 inhibitors may reduce the elimination rate of theophylline derivatives. CLINICAL EFFECTS: The concurrent administration of selected CYP1A2 inhibitors and theophylline or their derivatives may result in increased levels and toxicity of theophylline.(1-19) PREDISPOSING FACTORS: Concomitant therapy with inhibitors of CYP3A4 (e.g. clarithromycin, itraconazole, ritonavir) which block a secondary metabolic pathway for theophylline, may increase the magnitude of this interaction. PATIENT MANAGEMENT: Theophylline levels should be closely monitored in patients receiving concurrent therapy. The dosage of theophylline may need to be decreased after a CYP1A2 inhibitor is initiated. If the CYP1A2 inhibitor is discontinued in a patient stabilized on the combination, the theophylline level may fall. Monitor theophylline levels and adjust dose accordingly. DISCUSSION: A study in 5 patients with active hepatitis B and 4 healthy subjects examined the effects of a single dose of interferon alpha (9 million units in 8 subjects, 18 million units in 1 subject). There was no effect on theophylline in 1 subject. In the other 8 subjects, interferon increased theophylline half-life by 70% and decreased theophylline clearance by 49% (range 33% to 81%).(1) A study in 11 healthy subjects examined the effects of interferon alpha (3 million International Units daily for 3 days) on a single aminophylline (4 mg/kg) infusion. Interferon increased the half-life, area-under-curve (AUC), and mean residence time by 13.7%, 17.9%, and 16.3%, respectively. Theophylline clearance decreased by 9.1%.(2) In a study in healthy males, peginterferon alfa-2a (180 mcg once weekly for 4 weeks) increased theophylline AUC by 25%.(3,4) Concurrent interferon alfa has been shown to increase theophylline levels by 100%.(5) A study in 7 patients with chronic hepatitis C examined the effects of interferon beta (3 million to 9 million International Units daily for 8 weeks) on theophylline ethylenediamine (single 250 mg infusion). Interferon decreased theophylline clearance by 26.3% and increased theophylline half-life by 39.3%. There was no correlation between interferon dose and effect. The greatest effect was seen in a patient who received 3 million International Units daily, while no effect was seen in a patient who received 9 million International Units daily.(6) Increased serum theophylline levels with signs and symptoms of theophylline toxicity have been reported in patients following the addition of mexiletine to their treatment.(7-15) In a study evaluated the combination of disulfiram and theophylline in 20 recovering alcoholics. Patients received a single IV dose of theophylline while being given either 250 mg or 500 mg of disulfiram daily. Both dosages of disulfiram decreased the clearance of theophylline. However, the effect was greatest in patients receiving disulfiram 500 mg daily.(16) Increases in serum theophylline concentration and half-life have been reported during concurrent administration of theophylline and ticlopidine.(17) In healthy subjects, rofecoxib (12.5 mg/day, 25 mg/day, or 50 mg/day for seven days) increased the area-under-curve (AUC) of a single dose of theophylline (300 mg) by 38% to 60%. Therefore, the manufacturer of rofecoxib recommends that theophylline levels be monitored if rofecoxib is initiated or changed in patients receiving theophylline.(18) Selected CYP1A2 inhibitors linked to this monograph include: Angelica dahurica, artemisinin, cannabidiol, curcumin, danshen, dipyrone, disulfiram, echinacea, enasidenib, fexinidazole, genistein, ginseng, interferons, methoxsalen, mexiletine, parsley, phenylpropanolamine, pipemidic acid, piperine, propafenone, ribociclib, rofecoxib, rucaparib, simeprevir, ticlopidine, triclabendazole, verapamil.(19)	AMINOPHYLLINE, DYPHYLLINE, THEO-24, THEOPHYLLINE, THEOPHYLLINE ANHYDROUS, THEOPHYLLINE ER, THEOPHYLLINE ETHYLENEDIAMINE
Ustekinumab/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Ustekinumab, immunosuppressives, and immunomodulators all suppress the immune system.(1) CLINICAL EFFECTS: Concurrent use of ustekinumab with immunosuppressive or immunomodulating agents may result in an increased risk for serious infections.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: The US manufacturer of ustekinumab recommends caution because the concurrent use of ustekinumab with immunosuppressive agents may increase the risk of infection. If concurrent therapy is warranted, consider the risk of additive immune suppression and monitor based on prescribing information for both agents.(1) DISCUSSION: Ustekinumab has not been studied in combination with other immunosuppressants in psoriasis studies. In psoriatic arthritis studies, concomitant methotrexate use did not appear to influence the safety or efficacy of ustekinumab. In Crohn's disease and ulcerative colitis studies, concomitant use of immunosuppressants or corticosteroids did not appear to influence the safety or efficacy of ustekinumab. If concurrent therapy is warranted, consider the potential for increased immunosuppressive risks from both agents.(1) The most common infections reported by ustekinumab treated patients in the clinical trial periods included nasopharyngitis(8%) and upper respiratory tract infection(5%). Serious bacterial, mycobacterial, fungal, and viral infections were observed in patients receiving ustekinumab. Cases of interstitial pneumonia, eosinophilic pneumonia, and cryptogenic organizing pneumonia resulting in respiratory failure or prolonged hospitalization have been reported in patients receiving ustekinumab.(1)	IMULDOSA, OTULFI, PYZCHIVA, PYZCHIVA AUTOINJECTOR, SELARSDI, STELARA, STEQEYMA, USTEKINUMAB, USTEKINUMAB-AEKN, USTEKINUMAB-TTWE, WEZLANA, YESINTEK
COVID-19 Vaccines/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Immunosuppressants and immunomodulators may prevent the immune system from properly responding to the COVID-19 vaccine.(1,2) CLINICAL EFFECTS: Administration of a COVID-19 vaccine with immunosuppressants or immunomodulators may interfere with vaccine-induced immune response and impair the efficacy of the vaccine. However, patients should be offered and given a COVID-19 vaccine even if the use and timing of immunosuppressive agents cannot be adjusted.(1,2) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: In an effort to optimize COVID-19 vaccine response, the American College of Rheumatology (ACR) published conditional recommendations for administration of COVID-19 vaccines with immunosuppressants and immunomodulators.(1) The CDC also provides clinical considerations for COVID-19 vaccination in patients on immunosuppressants.(2) The CDC states that all immunocompromised patients over 6 months of age should receive at least 1 dose of COVID-19 vaccine if eligible. See the CDC's Interim Clinical Considerations for Use of COVID-19 Vaccines for specific recommendations based on age, vaccination history, and vaccine manufacturer.(2) The ACR states that in general, immunosuppressants and immunomodulators should be held for 1-2 weeks after each vaccine dose. See below for specific recommendations for certain agents.(1) The CDC advises planning for vaccination at least 2 weeks before starting or resuming immunosuppressive therapy.(2) Patients should be offered and given a COVID-19 vaccine even if the use and timing of immunosuppressive agents cannot be adjusted.(1,2) B-cell depleting agents, including rituximab: The ACR recommends consulting with the rheumatologist to determine optimal timing of COVID-19 vaccination. Measuring CD19 B cells may be considered to determine need for a booster vaccine dose. If B cell levels are not measured, a supplemental vaccine dose 2-4 weeks before the next scheduled dose of rituximab is recommended.(1) The CDC states that the utility of B-cell quantification to guide clinical care is not known and is not recommended. Patients who receive B-cell depleting therapy should receive COVID-19 vaccines about 4 weeks before the next scheduled dose. For patients who received 1 or more doses of COVID-19 vaccine during treatment with B-cell-depleting therapies that were administered over a limited period (e.g., as part of a treatment regimen for certain malignancies), revaccination may be considered. The suggested interval to start revaccination is about 6 months after completion of the B-cell-depleting therapy.(2) Abatacept: - Subcutaneous abatacept should be withheld for 1-2 weeks after each vaccine dose, as disease activity allows. - For intravenous abatacept, time administration so that vaccination will occur 1 week before the next abatacept infusion.(1) Cyclophosphamide: When feasible, administer cyclophosphamide one week after each COVID-19 vaccine dose.(1) Recipients of hematopoietic cell transplant or CAR-T-cell therapy who received one or more doses of COVID-19 vaccine prior to or during treatment should undergo revaccination following the current CDC recommendations for unvaccinated patients. Revaccination should start at least 3 months (12 weeks) after transplant or CAR-T-cell therapy.(2) TNF-alpha inhibitors and cytokine inhibitors: The ACR was not able to reach consensus on whether to modify dosing or timing of these agents with COVID-19 vaccination.(1) The CDC includes these agents in their general recommendation to hold therapy for at least 2 weeks following vaccination.(2) DISCUSSION: The ACR convened a COVID-19 Vaccine Guidance Task Force to provide guidance on optimal use of COVID-19 vaccines in rheumatology patients. These recommendations are based on limited clinical evidence of COVID-19 vaccines in patients without rheumatic and musculoskeletal disorders and evidence of other vaccines in this patient population.(1) The ACR recommendation for rituximab is based on studies of humoral immunity following receipt of other vaccines. These studies have uncertain generalizability to vaccination against COVID-19, as it is unknown if efficacy is attributable to induction of host T cells versus B cell (antibody-based) immunity.(1) The ACR recommendation for mycophenolate is based on preexisting data of mycophenolate on non-COVID-19 vaccine immunogenicity. Emerging data suggests that mycophenolate may impair SARS-CoV-2 vaccine response in rheumatic and musculoskeletal disease and transplant patients.(1) The ACR recommendation for methotrexate is based on data from influenza vaccines and pneumococcal vaccines with methotrexate.(1) The ACR recommendation for JAK inhibitors is based on concerns related to the effects of JAK inhibitors on interferon signaling that may result in a diminished vaccine response.(1) The ACR recommendation for subcutaneous abatacept is based on several studies suggesting a negative effect of abatacept on vaccine immunogenicity. The first vaccine dose primes naive T cells, naive T cell priming is inhibited by CTLA-4, and abatacept is a CTLA-4Ig construct. CTLA-4 should not inhibit boosts of already primed T cells at the time of the second vaccine dose.(1)	COMIRNATY 2025-2026 (12Y UP), COMIRNATY 2025-2026(5-11Y), MNEXSPIKE 2025-2026 (12Y UP), NUVAXOVID 2025-2026, SPIKEVAX 2025-2026 (12Y UP), SPIKEVAX 2025-2026 (6M-11Y)
Sarilumab/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Sarilumab, immunosuppressives, and immunomodulators all suppress the immune system.(1) CLINICAL EFFECTS: Concurrent use of sarilumab with immunosuppressive or immunomodulating agents may result in an increased risk for serious infections.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: The US manufacturer of sarilumab recommends caution because the concurrent use of sarilumab with immunosuppressive agents may increase the risk of infection. If concurrent therapy is warranted, consider the risk of additive immune suppression and monitor based on prescribing information for both agents.(1) DISCUSSION: Sarilumab was studied as monotherapy and in combination with methotrexate or conventional disease modifying antirheumatic drugs (DMARDs) in rheumatoid arthritis studies. Sarilumab has not been studied with biological DMARDs and concurrent use should be avoided. If concurrent therapy is warranted, consider the potential for increased immunosuppressive risks from both agents.(1) The most common infections reported by sarilumab treated patients in the clinical trial periods included pneumonia and cellulitis. Serious bacterial, mycobacterial, fungal, and viral infections were observed in patients receiving sarilumab. Cases of tuberculosis, candidiasis, and pneumocystis with sarilumab have been reported.(1)	KEVZARA
Ublituximab/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Ublituximab, immunosuppressives, and immunomodulators all suppress the immune system.(1) CLINICAL EFFECTS: Concurrent use of ublituximab with immunosuppressive or immunomodulating agents may result in an increased risk for serious infections.(1) PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications. PATIENT MANAGEMENT: The US manufacturer of ublituximab recommends caution because the concurrent use of ublituximab with immunomodulating or immunosuppressive agents, including immunosuppressant doses of corticosteroids, may increase the risk of infection.(1) If concurrent therapy is warranted, consider the risk of additive immune suppression and monitor based on prescribing information for both agents. When switching from agents with immune effects, the half-life and mechanism of action of these drugs must be taken into consideration in order to prevent additive immunosuppressive effects.(1) DISCUSSION: The most common infections reported by ublituximab-treated patients in the clinical trial periods included upper respiratory tract infections and urinary tract infections. Serious, including life-threatening or fatal, bacterial and viral infections were observed in patients receiving ublituximab.(1) Serious and/or fatal bacterial, fungal, and new or reactivated viral infections have been associated with other anti-CD20 B-cell depleting therapies. There were no cases of progressive multifocal leukoencephalopathy (PML) reported during the clinical trials; however, there have been reports of PML during or following completion of other anti-CD20 B-cell depleting therapies.(1)	BRIUMVI
Belimumab/Biologic Therapies SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Concurrent use of belimumab with other biologic therapies may result in additive or synergistic effects on the immune system.(1) CLINICAL EFFECTS: Concurrent use of belimumab with other biologic therapies may increase the risk of serious infections.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: The concurrent use of belimumab with other biologic therapies should be approached with caution.(1) DISCUSSION: In a randomized, double-blind, placebo-controlled trial, more patients who received belimumab and rituximab experienced serious adverse events, serious infections, and post-injection systemic reactions (22.2%, 9%, and 13.2%, respectively) than patients who received belimumab with placebo (13.9%, 2.8%, 9.7%) or standard therapy (19.7%, 5.3%, 5.3%).(1) The combination of belimumab with other biologic therapies has not been studied and should be used cautiously.(1)	BENLYSTA
Tocilizumab/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Tocilizumab, immunosuppressives, and immunomodulators all suppress the immune system.(1) CLINICAL EFFECTS: Concurrent use of tocilizumab with immunosuppressive or immunomodulating agents may result in an increased risk for serious infections.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: The US manufacturer of tocilizumab recommends caution because the concurrent use of tocilizumab with immunosuppressive agents may increase the risk of infection. If concurrent therapy is warranted, consider the risk of additive immune suppression and monitor based on prescribing information for both agents.(1) DISCUSSION: Tocilizumab was studied as monotherapy and in combination with methotrexate, non-biologic DMARDs or corticosteroids, depending on the indication. Tocilizumab has not been studied with biological DMARDs and concurrent use should be avoided. If concurrent therapy is warranted, consider the potential for increased immunosuppressive risks from both agents.(1) The most common infections reported by tocilizumab treated patients in the clinical trial periods included pneumonia, urinary tract infection, cellulitis, herpes zoster, gastroenteritis, diverticulitis, sepsis and bacterial arthritis. Serious bacterial, mycobacterial, fungal, and viral infections were observed in patients receiving tocilizumab. Cases of tuberculosis, cryptococcus, aspergillosis, candidiasis, and pneumocystosis have been reported.(1)	ACTEMRA, ACTEMRA ACTPEN, AVTOZMA, TOFIDENCE, TYENNE, TYENNE AUTOINJECTOR
Cladribine Oncology Inj/Immunosuppressives; Immunomodulators SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Cladribine in combination with immunosuppressives and immune-modulators all suppress the immune system.(1-4) CLINICAL EFFECTS: Concurrent use of cladribine with immunosuppressive or immune-modulating agents may result in an increased risk of serious infections.(1-4) PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications. PATIENT MANAGEMENT: Recommendations for cladribine regarding this interaction differ between regulatory approving agencies. The cladribine US, UK, and Australian prescribing information state: -Caution should be exercised if cladribine injection is administered before, after, or in conjunction with other drugs known to cause immunosuppression or myelosuppression.(1-3) The cladribine Canadian prescribing information states: -Proceed carefully in patients with severe bone marrow impairment of any etiology since further suppression of bone marrow function should be anticipated.(4) DISCUSSION: Severe bone marrow suppression, including neutropenia, anemia and thrombocytopenia, has been commonly observed in patients treated with cladribine injection, especially at high doses.(1-4)	CLADRIBINE

The following contraindication information is available for BETASERON (interferon beta-1b):

Overview
Contraindicated
Severe
Moderate

Drug contraindication overview.

*Avonex(R) and Rebif(R) are contraindicated in patients with a history of hypersensitivity to natural or recombinant interferon beta, albumin, or any other component of the formulation. *Betaseron(R) and Extavia(R) are contraindicated in patients with a history of hypersensitivity to natural or recombinant interferon beta, human albumin, or any other component of the formulation.

There are 0 contraindications.

There are 4 severe contraindications. Adequate patient monitoring is recommended for safer drug use.

Severe List
Depression
Disease of liver
Psychotic disorder
Suicidal ideation

There are 10 moderate contraindications. Clinically significant contraindication, where the condition can be managed or treated before the drug may be given safely.

Moderate List
Anemia
Chronic heart failure
Hyperbilirubinemia
Hypertriglyceridemia
Kidney disease with reduction in glomerular filtration rate (GFr)
Leukopenia
Lower seizure threshold
Neutropenic disorder
Seizure disorder
Thrombocytopenic disorder

The following adverse reaction information is available for BETASERON (interferon beta-1b):

Overview
Severe
Less Severe

Adverse reaction overview.

Interferon beta-1a (Avonex(R)): The most common adverse reactions (>=5%) in clinical studies were flu-like symptoms including chills, fever, myalgia, and asthenia. Interferon beta-1a (Rebif(R)): The most common adverse reactions in controlled clinical trials were injection site disorders, influenza-like symptoms, abdominal pain, depression, elevation of liver enzymes, and hematologic abnormalities. Interferon beta-1b (Betaseron(R)): The most common adverse reactions (>=5%) in clinical studies were injection site reaction, lymphopenia, flu-like symptoms, myalgia, leukopenia, neutropenia, increased liver enzymes, headache, hypertonia, pain, rash, insomnia, abdominal pain, and asthenia. Interferon beta-1b (Extavia(R)): The most common adverse reactions (>=5%) in clinical studies were injection site reaction, lymphopenia, flu-like symptoms, myalgia, leukopenia, neutropenia, increased liver enzymes, headache, hypertonia, pain, rash, insomnia, abdominal pain, and asthenia.

There are 34 severe adverse reactions.

More Frequent	Less Frequent
Abnormal hepatic function tests Hypertonia Injection site sequelae Leukopenia Lymphopenia Neutropenic disorder	Dermal necrosis Dyspnea Hypertension Injection site necrosis Lymphadenopathy

Rare/Very Rare
Abscess Anaphylaxis Anemia Bronchospastic pulmonary disease Capillary leak syndrome Cardiomyopathy Cellulitis Chronic heart failure Depression Drug-induced psychosis Hemolytic anemia Hemolytic uremic syndrome Hepatic failure Hepatitis Hypertriglyceridemia Pancreatitis Pulmonary arterial hypertension Seizure disorder Suicidal ideation Systemic lupus erythematosus Thrombocytopenic disorder Thrombotic thrombocytopenic purpura Worsening of chronic heart failure

Rare/Very Rare

Abscess
Anaphylaxis
Anemia
Bronchospastic pulmonary disease
Capillary leak syndrome
Cardiomyopathy
Cellulitis
Chronic heart failure
Depression
Drug-induced psychosis
Hemolytic anemia
Hemolytic uremic syndrome
Hepatic failure
Hepatitis
Hypertriglyceridemia
Pancreatitis
Pulmonary arterial hypertension
Seizure disorder
Suicidal ideation
Systemic lupus erythematosus
Thrombocytopenic disorder
Thrombotic thrombocytopenic purpura
Worsening of chronic heart failure

There are 46 less severe adverse reactions.

More Frequent	Less Frequent
Acute abdominal pain Chest pain Chills Fever Flu-like symptoms General weakness Headache disorder Hyperhidrosis Insomnia Myalgia Pain Skin rash	Abnormal vaginal bleeding Ataxia Cramps in legs Erectile dysfunction Increased urinary frequency Malaise Peripheral edema Urinary urgency Weight gain

Rare/Very Rare
Acute cognitive impairment Alopecia Anorexia Arthralgia Constipation Diarrhea Dizziness Dyschromia Dysmenorrhea Dyspepsia Hyperthyroidism Hypothyroidism Injection site infection Menorrhagia Mood changes Muscle weakness Nausea Palpitations Pruritus of skin Symptoms of anxiety Tachycardia Urticaria Vasodilation of blood vessels Vomiting Weight loss

The following precautions are available for BETASERON (interferon beta-1b):

Pediatric
Pregnant
Lactation
Geriatric

Although safety and efficacy of interferon beta in pediatric patients have not been established, the drug has been used with variable results for the management of childhood onset MS. In the PARADIGMS trial, a double-dummy randomized trial comparing fingolimod to interferon beta-1a by weekly intramuscular injection, fingolimod was superior to interferon in reducing relapsing rates. In another study that included a limited number of patients, treatment failure rates in children 10.5-17

years of age who received interferon beta-1a or beta-1b were higher than those reported in well-controlled studies in adults, but these results may be attributed to the selection of children with severe forms of childhood onset MS (i.e., with numerous relapses) or other unknown factors. Adverse effects reported when interferon beta was used in children were similar to those reported in adults.

Contraindicated

None

Severe Precaution

None

Management or Monitoring Precaution

None

There are no well-controlled studies in pregnant women; however, available data, including prospective observational studies, have generally not identified a drug-associated risk of major birth defects with the use of interferon beta during pregnancy. Findings regarding a potential risk for low birth weight or miscarriage with the use of interferon beta in pregnancy have been inconsistent. In a study in pregnant monkeys, administration of interferon beta during pregnancy resulted in an increased rate of abortion at doses greater than those used clinically; however, it is unclear whether, as a class of products, administration of interferon beta therapies to pregnant animals at doses greater than those used clinically results in an increased rate of abortion.

Use interferon beta during pregnancy only if the potential benefits justify the possible risks to the fetus. A population-based cohort study collected data from 1996--2014 in Finland and from 2005-2014 in Sweden for 2,831 pregnancy outcomes in women with MS. In 797 of the pregnancies, women were exposed to only interferon beta; no evidence for an increased risk of birth defects was identified in comparison of women with MS exposed to interferon beta, and women with MS that were not exposed to any non-steroid therapies within the study.

Increased risk of miscarriage or ectopic pregnancy was not observed; however, data for these outcomes may have been incomplete, making interpretation of the findings more difficult. Two smaller cohort studies that collected data on women exposed to interferon beta during pregnancy found that a decrease in mean birth weight may be associated with interferon beta exposure during pregnancy; however, this finding has not been replicated in larger observational studies. Additionally, two small studies observed an increased rate of miscarriage, with only one study determining the findings to be statistically significant. In a small cohort study, an increased risk of preterm birth was observed following exposure to interferon beta.

Limited data suggest that interferon beta-1a distributes into human milk. There are no data on the presence of interferon beta-1b in human milk. It is not known whether interferon beta has any effects on the breastfed infant or on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for interferon beta and any potential adverse effects on the breastfed child from the drug or from the underlying maternal condition.

Clinical studies of interferon beta did not include sufficient numbers of patients >=65 years of age and older to determine whether geriatric patients respond differently than younger patients.

Relapsing form of multiple sclerosis
G35	Multiple sclerosis
G35.A	Relapsing-remitting multiple sclerosis
Secondary progressive multiple sclerosis
G35	Multiple sclerosis
G35.C	Secondary progressive multiple sclerosis
G35.C0	Secondary progressive multiple sclerosis, unspecified
G35.C1	Active secondary progressive multiple sclerosis